Income Tax Calculator

What an income tax calculator does

An income tax calculator estimates what you owe the federal government on a year's income, after the deductions and credits you are entitled to. Its real value is not just the final number but the breakdown: it shows how your income is split across tax brackets, what your taxable income actually is after deductions, and the gap between the rate on your last dollar and the rate on your income as a whole. Understanding those three things removes most of the confusion — and the fear — people have about how income tax works.

How progressive income tax works

A progressive system does not apply one rate to your whole income. Your taxable income is divided into bands (brackets), and each band is taxed at its own rate. The first slice of income is taxed at the lowest rate, the next slice at a higher rate, and so on. Only the income that falls inside a given band is taxed at that band's rate — a point the calculator makes concrete by showing the tax generated in each bracket. This calculator applies the selected tax year's published federal brackets and standard deduction for your filing status.

From gross income to taxable income

• Total income = gross income + other taxable income
• Less pre-tax deductions (traditional retirement contributions, HSA, etc.)
• Less the standard deduction or your itemized deductions, whichever is larger
• = taxable income, to which the brackets apply

The distinction between total income and taxable income is where most surprises hide: the brackets never touch your gross salary directly, only what is left after deductions.

Marginal vs effective tax rate

These two rates answer different questions and are constantly confused. Your marginal rate is the rate on your next (or last) dollar of income — your top bracket. Your effective rate is total tax divided by total income, and it is always lower, because the income in your lower brackets was taxed at lower rates. Someone in the 22% bracket does not pay 22% of everything; their effective rate might be 12–14%. When you evaluate whether an extra dollar of income or a deduction is worth it, the marginal rate is the one that matters; when you compare your overall tax burden year to year, use the effective rate. See the split band by band in the tax bracket calculator.

Deductions vs credits

Both lower your tax, but not equally. A deduction reduces the income that is taxed, so its value depends on your marginal rate — a $1,000 deduction saves $220 at a 22% rate. A credit reduces the tax itself, dollar for dollar, so a $1,000 credit saves $1,000 regardless of your bracket. That is why credits are generally more valuable than deductions of the same size. Enter your credits to see them applied after the bracket calculation.

Worked example

Take a single filer with $80,000 of gross income and a $6,000 pre-tax retirement contribution. Subtracting the contribution and the standard deduction leaves a taxable income well below $80,000. The brackets then tax the first band at the lowest rate, the next band higher, and so on — so although this filer sits in the 22% marginal bracket, only the income above that bracket's threshold is taxed at 22%, and the effective rate ends up far lower. Adjust the contribution or add a credit and the calculator re-runs every band instantly.

Where this fits

Income tax is one layer of what leaves your paycheck. To see the whole picture including Social Security and Medicare, use the take-home pay calculator; if you are self-employed, the self-employment tax calculator and quarterly tax calculator add the pieces that a salaried employee's employer would otherwise handle.